1. Field of the Invention
The present invention relates in general to a loading apparatus for a recording medium. More specifically, the present invention relates to a loading apparatus capable of loading various types of recording media.
2. Description of Related Art
A conventional recording medium loading apparatus installed in a disc apparatus having exchangeable property for a plurality of disc recording media (referring to compatible disc apparatus hereinafter) is used as an example for description. For example, a disc apparatus used as a device for reproducing or recording information is built in or externally connected to an electronic apparatus, such as a personal computer or a word processor. The disc apparatus uses the disc-shaped recording medium as its recording medium. In addition, the disc-shaped recording medium is loaded into the disc apparatus using a recording medium loading apparatus and is then reproduced or recorded.
On the other hand, a variety of disc recording media are also provided, for example CD (Compact Disc), CD-R (Compact Disc-Recordable), CD-ROM (Compact Disc-Read Only Memory), CD-RW (Compact Disc-Rewritable), DVD-ROM (Digital Versatile Disc-Read Only Memory), DVD-RAM (Digital Versatile Disc-Random Access Memory) are well known. In addition, there are two kinds of recording medium: one is the disc with a diameter of 12 cm, and the other is the disc with a diameter of 8 cm. Moreover, for the DVD-RAM, three kinds can be classified, including wherein the disc is enfolded in a cartridge.
As described above, although a variety of disc-shaped recording media is provided, it would be convenient if the reproducing and/or recording process for each disc-shaped recording medium could be performed by one disc apparatus. Therefore, a compatible disc apparatus having the exchangeable property for each disc-shaped recording medium is provided.
A variety of the disc-shaped recording media have to be transferred in the main body of the disc apparatus for the compatible disc apparatus. Conventionally, for the recording medium loading apparatus, a tray is used as the transferring device in the main body of the disc apparatus.
The tray can be drawn out of the main body of the disc apparatus when the disc-shaped recording medium is loaded or ejected (referring to eject time, hereinafter). In addition, loading recesses are formed on a disc loading surface of the tray for loading the 12 cm disc, 8 cm disc and the disc cartridge, thereby a variety of the disc-shaped recording media can be loaded on the tray.
For the conventional compatible disc apparatus, because the tray is installed for loading the disc-shaped recording media, it is necessary for the tray to be greatly drawn out of the main body of the disc apparatus when the disc-shaped recording media are loaded to or removed from the tray. Therefore, for the conventional compatible disc apparatus, when the disc apparatus is installed, it is necessary to estimate the drawing distance of the tray in advance for setting required space, which becomes a problem in that the installation space becomes large.
Furthermore, an external force is easily applied to the tray when the tray is greatly drawn out of the main body of the disc apparatus. Therefore, for the structure using the tray to transfer the disc-shaped recording media, there is a problem that malfunction is easily caused due to the applied external force.
In addition, a recording medium loading apparatus without using a tray is provided for solving the foregoing problems, wherein the outer circumference of the disc-shaped recording media is clamped by a clamp lever, and then drawn into the main body of the disc apparatus. However, the structure using the clamp lever has to stop the clamp lever at a plurality of positions in the apparatus.
Namely, for the recording medium loading apparatus using a tray, even if the disc-shaped recording media are of different types, the center position (clamped position) for each disc-shaped recording medium is the same when the disc is loaded on the loading recess of the tray. Therefore, it is not necessary to change the bringing-in position of the tray according to the different types of the disc-shaped recording media.
However, for the recording medium loading apparatus using the clamp lever, because the outer circumference (for example, the front end of the insertion direction) of the disc-shaped recording media is held by the clamp lever, the position of the clamp lever clamping the 8 cm disc to the turntable and the position of the clamp lever clamping the 12 cm disc to the turntable are different. With respect to the position of the clamp lever clamping the 8 cm disc to the turntable, the position of the clamp lever clamping the 12 cm disc to the turntable is in the more inner position relative to the insertion direction. Similarly, the position that each disc is clamped by the clamp lever, and the retrocede position without impeding the rotation of the disc when the disc is loaded onto the turntable are also different for different kinds of discs.
Therefore, as described above, when the clamp lever control movement is performed, it has to stop the clamp lever at each stop position set for each different discs. Low cost and high reliability on/off switches are used to detect the stop position of the clamp lever. The on/off switches are installed on the predetermined stop positions of the clamp lever, and the stop positions of the clamp lever can be detected because the on/off switches are pressed by the clamp lever when the clamp lever is moved.
If only one kind of disc is transferred by the clamp lever, the number of the installed on/off switches is small because the stop positions of the clamp lever are few (for example, 3 stop positions). However, for the compatible disc apparatus capable of loading a plurality of kinds of discs, there are many stop positions for the clamp lever.
For example, if each of three kinds of discs has three stop positions, a total of nine on/off switches are required.
Therefore, when the stop positions of the clamp lever are detected by the conventional method using the on/off switches, the number of required switches is increased. As a result, the part number of the recording medium loading apparatus is increased and therefore the structure becomes complicated, resulting incost increase.
To solve the foregoing problems, a tray is not used in the recording medium loading apparatus. The recording medium is clamped by a clamp lever and then brought into the main body of the disc apparatus. However, for a structure using a clamp lever, the operation of the motor driving the clamp lever is started when the disc-shaped recording medium is gripped by the clamp lever. At this time, the conventional motor driving the clamp lever is fully operational.
Therefore, for the conventional recording medium loading apparatus, the operator of the compatible disc apparatus cannot stop the disc-shaped recording medium from transferring even if the operator immediately notices that a different disc-shaped recording medium has been inserted by mistake. In the case that a different disc-shaped recording medium has been inserted by mistake, the disc-shaped recording medium cannot be exchanged for another unless it has been completely loaded to the loaded position (the position for performing the reproducing and/or recording process), resulting in a problem of bad usability.